Sliding panels, particularly panels for such use as patio doors, or windows, are well known in the construction industry. Most sliding patio doors, for example, comprise a structure having two panels, one of which is fixed and the other of which is the moveable or operating panel. Each of the two panels is mounted on a separate track, in such a manner that the moveable or operating panel is mounted so as to move on the interior side of the fixed panel. Because the moveable panel is mounted in a separate track, sufficient clearance must be made between the panels, particularly at the place where the side sash members of the panels overlap. A number of difficulties and problems arise from such structures, particularly having to do with rendering the structure weathertight, and providing satisfactory thermal performance with respect to heat loss through air infiltration or exfiltration past and around the sliding door structure.
Other sliding door structures are known for such purposes as closets or cabinets, where it is desired to disguise moveable panels, or to provide a structure whereby two sliding doors can be arranged for movement, one with respect to the other, having a single suspension or guide track.
In the latter instances, the prior art provides several examples of structures where two panels are substantially co-planar or in line with each other, when they are both in their closed positions.
For example, GROSSMAN U.S. Pat. No. 2,819,498, issued Jan. 14, 1958, shows a sliding door arrangement with a switching system whereby one door can be moved rearwardly with respect to the other door, and then moved in a track behind the other door so as to bypass it.
Another example is shown in CHENG, U.S. Pat. No. 3,841,024, issued Oct. 15, 1974, where a sliding window arrangement is shown having a fixed and a sliding window, where the sliding window panel is pushed rearwardly then slid open on it's own track.
HENNING, in U.S. Pat. No. 3,293,801, issued Dec. 27, 1966, shows an apparatus for mounting sliding doors in a cabinet, where the door to be moved is pulled into a position outward from the other door, having an articulation in respect of the mounting means such that the door to be moved is suspended or supported from a door carriage in one of two positions which are displaced horizontally inwardly or outwardly with respect to the plane of movement of the door.
Likewise, RUTHERFORD, in U.S. Pat. No. 2,680,268, issued June 8, 1954, discloses a moveable panel structure whereby either of two panels which are intended for closures for closets and the like may be moved sideways by first displacing one of the panels forwardly with respect to the other and thence accommodating a sideways movement of either on its own independent track. In the case of RUTHERFORD, one panel which is displacable inwardly and outwardly with respect to the closure plane is supported at its sides by a pair of spaced vertical rods to which the panel is hingedly connected. Thus, the rods are rotatable with respect to fixed guides, and the panel is moveable inwardly and outwardly with respect to the plane in which the rods are always maintained, which plane lies behind the plane in which the panels are located when they are both closed.
A structure such as that particularly described by RUTHERFORD is, however, of little value where it is intended that it should be placed in a window or door opening in the exterior wall of a building, such as a home, office or factory. This is particularly because there is no structure nor any contemplation of any means by which the panels can be sealed against weather, and so as to substantially preclude air infiltration or exfiltration.
In the standard sliding window or door structure of the usual sort, particularly sliding patio doors, the sash frames of the panels and the outer frames within which the structure is fitted are now usually formed of extruded aluminum. Weather stripping, door sweeps and the like are provided, formed of such materials as a loose fibrous polypropylene pile, or of flexible vinyl or neoprene, for example. However, where one panel such as a patio door is mounted in its own track so as to clear the other panel--so that, when opened, substantially one half of the entire wall opening filled by the window or door structure is open for passage therethrough--some particular problems with respect to weather and air leakage exist. Moreover, because aluminum is, itself, a good thermal conductor, it is important to provide a structure having a thermal break formed therein, so as to avoid conduction losses of heat.
Recently, considerable attention has been given to means and structures whereby energy losses can be minimized. The present invention assists such aims and objectives, by providing a door or window structure where one panel is fixed and the other is moveable, such as in a patio door structure, and which overcomes problems of the prior art in respect of its seal against weather and its thermal performance against heat loss.
Moreover, the present invention provides a structure by which large moveable panels of the sort used for patio doors, may be easily moved, and easily re-positioned from a fully closed to a fully open position.
Still further, the present invention provides a structure which may be substantially tamper-proof, thereby providing security against unwanted intrusion.
What the present invention provides therefor, is a structure which has the storage or in-line features of a caseme window or door installation; together with the out-of-plane sliding features of a sliding door or window installlation.
Three principal embodiments of the present invention are discussed in greater detail hereafter. In the first embodiment, a rack and pinion driving connection is made between two control rods within the sash structure of the moveable panel; in the second embodiment, a direct driving connection is made between the control rods; and in the third embodiment, a direct driving, fixed cable connection is made between the control rods.
Of more importance, however, is the fact that the present invention provides a structure which minimizes heat loss as well as inside surface condensation in a door or window installation, where all of the sealing members or gaskets are readily available for inspection and replacement if necessary, and by which the sealing gaskets are totally unhindered by mounting hardware or the like.
According to standards presently in force in Canada, having to do with residential sliding doors and windows, air infiltration allowed for a sliding door or window unit must not exceed 0.75 cu.ft./min./sq.ft. of overall frame size. Air infiltration of the non-operating or fixed panel must not exceed 0.06 cu.ft./min./sq.ft. of overall frame size; i.e., approximately 8% of that permitted for the sliding unit.
The present invention is intended to provide far better air infiltration performance than that minimally required by such as the National Building Code of Canada, and does so by providing for a horizontally sliding structure which is supported at its four corners, and moves as a unit by pivoting around the support points at the four corners from a closed to a sliding position or vice versa--i.e., forwards or backwards with respect to the plane in which the panel is either in its closed position or its sliding position.
To effect the above objects, the present invention provides a door or window structure intended to be fitted in door or window openings in exterior walls of buildings, which structure has an outer frame, and first and second panels which are each approximately of equal size to each other. The first panel is substantially fixed in place and the second panel is moveable from a first, closed, position to a second, fully open, position; such that when the second panel is in the first position, it is substantially co-planar with the first panel, and when the second panel is in the second position, it is substantially co-extensive within the outer frame with the first panel, and on the interior side of the window structure. At least the second panel has a sash frame, having within it and at each side thereof a substantially rigid control rod, where each control rod is rotatably mounted within the sash frame and is securely connected at its top and bottom ends with a cam member. Each of the cam members has a guide member secured to it for engagement with a co-operating guide track, and each guide member is rotatable with respect to its co-operating guide track. A fixed tie means, which may be a tie rod or a fixed cable, is placed between the control rods, so that rotation of one of the control rods causes an equal rotation in the same direction of rotation of the other of the control rods. At the exterior side of the second panel when it is in its closed position, there is an opening in the frame, which opening is of lesser size than the second panel. A first compressible gasket surrounds the opening at the interior side thereof, and is placed so as to contact a co-operating portion of the exterior surface of a second panel so that when it is in its closed position, the gasket is at least partially compressed. A second gasket is also placed within the outer frame at the interior side thereof, in such a place as to contact a second co-operating portion of the exterior surface of the second panel when the panel is closed, so that the second gasket is flexed, and a substantially isolated pocket is formed within the outer frame between the first and second gaskets, substantially around the periphery of the exterior surface of the second panel. The isolated pocket serves to equalize air pressure between the interior and exterior sides of the door or window structure.
As will be described in greater detail hereinafter, there are several alternative embodiments as to the linkage arrangement between the control rods and the tie rod, and as to the co-operation of the guide members--particularly the lower guide members--with the respective guide track.